Busbars for electrically connecting battery cells to one another in parallel or serial fashion are known from the prior art. Busbars of this kind use an electrically conductive metal sheet and sheet metal connector pieces protruding from it, which are electrically connected to the battery cells. To this end, the sheet metal connector pieces each have a contacting part that is welded to a pole of a battery cell. The sheet metal connector pieces are incorporated into the metal sheet with the aid of a cutting method such as incision—which can be carried out by means of stamping or laser cutting.
It is also known (EP2337115A2) to provide such sheet metal connector pieces with a safety part that embodies an electrical fuse on the sheet metal connector piece and protects the connected battery cell from a safety-critical amperage. This fuse is implemented in the form of a constriction of the cross-section of the sheet metal connector piece. Such a constriction resistance, however, has the disadvantage of decreasing the mechanical strength of the sheet metal connector piece, which increases the risk of a mechanical line break in the event of physical shocks or vibrations. A reduced durability of the busbar, particularly when used in mobile applications, must be expected.
In order to counteract this disadvantage, for example EP2608243A1 proposes coating the sheet metal connector piece with a resin in the safety part. But this is not only complex in design, it can also disadvantageously increase the fire hazard, particularly when this fuse is activated.